1. Field of the Invention
The present invention relates to an apparatus and method for incrementally enhancing dialogue knowledge through self-learning, and more particularly, to an apparatus and a method which determine a speech of a user, which a dialogue system cannot understand, in a dialogue between the user and the dialogue system to enhance a performance of the dialogue system.
2. Description of Related Art
Only when a spoken dialogue system and a text-based dialogue system have dialogue knowledge necessary for having a dialogue with a user, the spoken dialogue system and the text-based dialogue system can appropriately respond to an utterance of the user. Generally, since dialogue knowledge is established by developers or experts in application field, the cost, a storage space, or a development time is limited, and for this reason, the dialogue knowledge is inevitably established in the limited field and range. Therefore, generally, the application field of the dialogue system is limited due to the limited dialogue knowledge.
In order to provide a dialogue system for various fields such as information services and education, developers and knowledge experts should develop massive dialogue knowledge in consideration of various situations, and moreover, after the development, an operation of collecting dialogue logs for a certain duration, analyzing the collected dialogue logs, and adding and establishing insufficient dialogue knowledge to augment dialogue knowledge is needed for processing various utterances of a user.
Such a service enhancement operation should be periodically repeated for responding to new requests of users, but since a complicated operation should be performed for designing a dialogue model for the new requests and establishing dialogue knowledge based on the dialogue model, the new requests cannot easily be applied to a dialogue system which has been already developed and is being used.
Therefore, in the related art dialogue system, much time and cost are needed for reflecting new user requirements, and a technical solution for applying the new user requirements to a system which is operating should be solved.
However, users can distinguish a speech easily recognized by the system and an unrecognized speech through learning before correction for the error is reflected, and thus, an update operation which expends time and cost could be meaningless to users.
For this reason, since a dialogue system capable of recognizing speeches of all users should understand speeches of users which are not frequently used, much time and cost are consumed at an initial stage.
Korean Patent Application Publication No. 10-2011-0072847 discloses a dialogue management system and method and relates to a method which, when an intention of a user is relevant to a subject unprepared by a dialogue system, induces the user to a dialogue suitable for an aim of the dialogue system and performs the induced dialogue. However, the dialogue management system and method cannot solve a problem of the related art which cannot update or enhance the dialogue system when an intention of a user is misunderstood or a system suitable for the intention of the user is not prepared.
U.S. Patent Application Publication No. 2014/0188477 discloses a method of correcting a response in a natural language dialogue system. When a user asks an additional question because a response list of a system for a first speech of the user is inaccurate, the method again provides a response list except a response to the first speech to increase an accuracy of a response. However, the method also has a technical substance for finding an optimal response from among responses of a related art system, and thus, if a response desired by the user is not stored in the system, it is unable to provide an appropriate response.